Power semiconductor devices like MOSFETs (metal oxide semiconductor field effect transistors) sustain a high breakdown voltage in a blocking mode and have a low on-state resistance in a conductive mode. Power semiconductor devices therefore usually include a drift region between a voltage-controlled body region and a drain region. Increasing the length of the drift zone increases the voltage blocking capability but at the same time increases the on-state resistance. A power semiconductor device may integrate two or more functional blocks implementing transistor functionalities and being arranged in series, in parallel or in other configurations in the same semiconductor die to implement specific functions and/or to obtain specific device characteristics. Structures between the functional blocks sustain potential differences between the functional blocks. It is desirable to provide reliable semiconductor devices and methods that provide a simple and cost effective manufacturing process.